中国南沙群岛的双壳纲贝类

报道了中国南沙群岛的双壳纲贝类141种,分隶于5亚纲8目36科77属.从种类的组成中,帘蛤科有18种,蚶科15种,扇贝科11种,鸟蛤科10种,锉蛤科8种,贻贝科、海菊蛤科和樱蛤科各7种,砗磲科6种,其他各科的种类均在5种以内.按种的性质而论,大多数属于和珊瑚礁有密切联系的热带种或亚热带种,区系性质为印度-西太平洋区的印尼-马来亚区.     

Molecular phylogeny of the genus Clibanarius(Decapoda: Anomura: Diogenidae) based on mitochondrial and nuclear DNA sequences

Clibanarius,a genus of hermit crabs,is one of the most diverse genera within Diogenidae.However,studies on the phylogeny within Clibcanarius is very limited.We reconstruct the molecular phylogeny of the genus Clibanarius based on two mitochondrial(16 S rRNA and COI)and two nuclear protein-coding(NaK and PEPCK)genes using a multigene phylogenetic approach.Eleven selected Clibanarius species from the Indo-West Pacific are analyzed and the Bayesian and maximum likelihood analyses produced identical results in topology.Results suggest that C.rutilus and C.infraspinatus are more closely related to each other than to C.snelliusi,and C.striolatus shows a close relationship to C.longitarsus.The close association of C.merguiensis with C.englaucus and C.humilis is strongly supported by the divergence of C.virescens from them.Our phylogenetic results contradict the morphological classification scheme proposed for Clibanarius and indicate that the relative length of dactyls and propodi is not phylogenetically significant in Clibanarius.In addition,we speculate that the morphological characteristic of the median cleft of the telson might be phylogenetically important for Clibanarius.     

雷州半岛红树林海区的鱼类种类调查

对雷州半岛8个红树林分布区设站位进行了生物多样性调查,其中获得鱼类127种,分别隶属于15目58科100属。以鲈形目最多,共27科49属65种,占51.2％。种类出现最多的科为(鱼叚)虎鱼科。采获种类最多的站位为北潭。各站位之间鱼类种类具有一定的差异性。调查获得的鱼类体型偏小,大部分种类具有食用价值,其中16种已为人工增养殖的对象。     

越南沿海的双壳纲软体动物

报道了越南沿海的双壳纲软体动物 32 0种 ,隶属 3亚纲、6目、2 6总科、4 1科、1 4 8属。从种类的组成中 ,帘蛤科有 5 7种 ,蚶科 32种 ,樱蛤科 2 9种 ,贻贝科 2 5种 ,鸟蛤科 1 6种 ,牡蛎科 1 4种 ,蛤蜊科 1 3种 ,珍珠贝科和扇贝科各 1 2种 ,紫云蛤科 1 1种 ,竹蛏科 1 0种 ,其他各科的种类均在 7种以内。按种的性质而论 ,越南沿海主要是由热带种和亚热带种类组成 ,还有与珊瑚礁紧密联系的热带种。就越南沿海双壳纲软体动物分类区系而论 ,应属印度—西太平洋区的印尼—马来亚区。     

A preliminary phylogenetic analysis of Luidia (Paxillosida: Luidiidae) from Chinese waters with cytochrome oxidase subunit I (COI) sequences

Luidia Forbes (Paxillosida: Luidiidae) are common soft bottom sea stars with 49 described species. Because of substantial morphological diversity, the taxonomy of the genus is complex and hasn’t been resolved definitely. In order to resolve general taxonomic issues, and determine species boundaries and phylogenetic relationships within the genus Luidia, the sequences of cytochrome oxidase subunit I (COI) gene from 24 specimens of Luidia, belonging to eight taxa in Chinese waters, were studied. Three sequences of two species in genus Luidia from GenBank were used to analyze the phylogenetic relationships. The molecular phylogeny exhibited three main clades, each with strong bootstrap support: Clade A including Luidia quinaria from the Sea of Japan; Clade B including seven nominal species (L. quinaria von Martens, L. yesoensis Goto, L. changi Liu, Liao and Li, L. orientalis Fisher, L. avicularia Fisher, L. longispina Sladen and L. hardwicki Gray) from Chinese waters; and Clade C including L. maculata Müller & Troschel from Chinese waters. Our molecular phylogeny results support the morphological Quinaria-Group and Alternata-Group assigned by Döderlein. Seven nominal species we sampled do not exhibit genetic distances that are large enough to recognize them as separate species. Cryptic species may exist in’ Luidia quinaria’ from the Yellow Sea and the Sea of Japan. Meaningful morphological characters need further investigation in Luidia.     

Polyphasic examination on Merismopedia tenuissima CHAB 7021 from Ganjiang River,China revealed the polyphyly of the genus Merismopedia(Cyanobacteria)

Species in the cyanobacterial genus Merismopedia are present in freshwaters at different trophic levels, with some species even as the components of cyanobacterial blooms. However, species diversity in this genus was not fully verified by molecular investigation and polyphasic taxonomic studies. In this study, Merismopedia-like strain tenuissima CHAB 7021 was isolated from Ganjiang River in Jiangxi Province, China, and polyphasic characterization of this strain was performed by morphological observation, ultrastructural examination, chemical detection of pigments and phylogenetic analysis based on 16 S rRNA gene sequences. Morphological identification of the strain was supported by the ultrastructural features, as the tiny species Merismopedia tenuissima Lemmermann. The phylogeny based on 16 S rRNA gene sequences revealed at least three clades formed by the strains of Merismopedia. The three M. tenuissima strains including M. tenuissima CHAB 7021 was gathered in clade III with distant relationship to the clade I formed by the six Merismopedia strains including the type species M. punctata, and such a genetic distance may propose Merismopedia tenuissima to separate from Merismopedia genus. However intermixture relationship in between strains of M. punctate and M. glauca in the phylogenetic tree still complicated the taxonomic status in the genus Merismopedia. The process for taxonomic revision in the Merismopedia genus still await for examination and further information on more strains of type species M. punctata.     

Molecular phylogeny of oligotrich genera Omegastrombidium and Novistrombidium (Protozoa, Ciliophora) for the systematical relationships within Family Strombidiidae

The phylogeny of the oligotrich ciliates is currently a hot debate despite the availability of both morphological and molecular data. In the present paper, further small subunit rRNA (SS rRNA) genes were analyzed from the Genera Omegastrombidium and Novistrombidium, as well as from Strombidium, and combined with three new SS rRNA sequences from Strombidium basimorphum, S. sulcatum population QD-1, and Novistrombidium testaceum population GD. The phylogenetic positions of these organisms were inferred using Bayesian inference, Maximum Likelihood, and Maximum Parsimony methods. The main results are: (1) the SS rRNA gene sequence analyses match the recent findings about the molecular evolution of oligotrichs, indicating that the family Strombidiidae is paraphyletic; (2) the Genus Omegastrombidium is separated from the Genus Strombidium, as shown in recent cladistic analyses; (3) morphospecies in Genus Novistrombidium, based on similarity of somatic ciliature, are separated from each other in all topological trees, indicating that this genus could be a paraphyletic group; (4) the molecular data indicate a possibility of paraphyly for the genus Strombidium; and (5) the similarities of the SS rRNA gene of specimens identified as S. sulcatum and S. inclinatum are 99.8%–100%. However, present knowledge on the oligotrichs sensu stricto is still insufficient and further studies based on both molecular and other technologies are required.     

Molecular phylogeny and evolution of Scomber (Teleostei: Scombridae) based on mitochondrial and nuclear DNA sequences

A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial (COI, Cyt b and control region) and nuclear (5S rDNA) DNA sequence data in multigene perspective. A variety of phylogenetic analytic methods were used to clarify the current taxonomic Classification and to assess phylogenetic relationships and the evolutionary history of this genus. The present study produced a well-resolved phylogeny that strongly supported the monophyly of Scomber. We confirmed that S. japonicus and S. colias were genetically distinct. Although morphologically and ecologically similar to S. colias, the molecular data showed that S. japonicus has a greater molecular affinity with S. australasicus, which conflicts with the traditional taxonomy. This phylogenetic pattern was corroborated by the mtDNA data, but incompletely by the nuclear DNA data. Phylogenetic concordance between the mitochondrial and nuclear DNA regions for the basal nodes Supports an Atlantic origin for Scomber. The present-day geographic ranges of the species were compared with the resultant molecular phylogeny derived from partition Bayesian analyses of the combined data sets to evaluate possible dispersal routes of the genus. The present-day geographic distribution of Scomber species might be best ascribed to multiple dispersal events. In addition, our results suggest that phylogenies derived from multiple genes and long sequences exhibited improved phylogenetic resolution, from which we conclude that the phylogenetic reconstruction is a reliable representation of the evolutionary history of Scomber.     

湛江沿海鱼类补遗

增补湛江市沿海鱼类种类有51种,隶属于11目39科45属,其中软骨鱼类8种;硬骨鱼类43种,(鲈形目30种)。现知湛江市沿海鱼类有222种。     

A new genus and species of shrimp(Crustacea:Axiidea:Axiidae) from the Caroline Ridge,Northwest Pacific

A new genus and species of axiid shrimp,Carolinaxius kexuae gen.et sp.nov.is described and illustrated based on a single specimen collected from an unnamed seamount in the Caroline Ridge,Northwest Pacific.Although both chelipeds are mis sing,the specimen can be distinguished from other axiid genera by a combination of characteristics:narrowly triangular ro strum;median carina and lateral gastric carina each with one prominent tooth;submedian gastric carinae converging po steriorly,with teeth;cornea weakly pigmented,eyestalk with acute distome sial tooth on dorsal surface;male pleopod 1 two-articled;pleopod 2 with appendix interna and appendix masculina;pleopods 3-5 with appendix interna.The molecular phylogeny suggests the new genus is most closely related to another recently described genus living inside hexactinellid sponges on seamounts in the Indian Ocean,Montanaxius Dworschak,2016.However,it differs from Montanaxius in the shape of the rostrum,the arrangement of teeth on the carapace,and the shape of the eyestalk.Besides,the significant molecular differences support the two belonging to different genera.     

Species identification and phylogenetic analysis of genus Nassarius (Nassariidae) based on mitochondrial genes

Genus Nassarius contains many subgenera, such as Zeuxis, Telasco, Niotha, Varicinassa, Plicarcularia, Nassarius s. str. and Reticunassa. On the basis of morphological characteristics of the shell and radula and sequences of mitochondrial cytochrome oxidase subunit I (COI) and 16S rRNA genes, Nassarius specimens collected from the South China Sea were identified and phylogenetically analyzed. Although Nassarius sp. and Nassarius (Varicinassa) variciferus were morphologically different in their shells, few variations were found among their radular teeth and sequences of mtCOI and mt16S RNA genes. Therefore, Nassarius sp. should be classified as N. (Varicinassa) variciferus. Nassarius (Zeuxis) sp. has only a subtle difference from Nassarius (Zeuxis) algidus on the shell, but it shows obvious differences in radular teeth and DNA sequence, indicating that they are two distinct species. Sequence divergence of mtCOI and mt16S RNA genes within Nassarius species was much lower than that between species, suggesting that these two genes are suitable for Nassarius species identification. Phylogenetic analysis (neighbor-joining and maximum parsimony) based on mtCOI and mt16S rRNA genes revealed the presence of two groups in genus Nassarius and a closest relationship between subgenera Zeuxis and Telasco. Species of subgenus Plicarcularia did not form a single clade. The molecular phylogeny was not congruent with the previous morphological phylogeny. The subgeneric divisions of genus Nassarius appear to be uncertain and unreliable.     

Relationships between two Pseudoalteromonas strains isolated from the Canada Basin and the Southern Ocean using a polyphasic approach

The evolutionary relationships and taxonomic position of two marine planktonic bacterial strains BSw20211 and BSw10014, isolated from the Canada Basin and from the Southern Ocean, respectively, were determined using a polyphasic taxonomic approach. There was a close phylogenetic relationship between the two strains and most phenotypic properties were shared. Nonetheless, they were found to belong to different species of the genus Pseudoalteromonas on the basis of genotypic analyses. Findings were consistent with the suggestion that gyrB gene sequence comparison and DNA-DNA relatedness might better define phylogenetic relationships of bacteria at the species level. However, a cut-off value of 90% gyrB gene sequence similarity was not reliable for the differentiation of species within the genus Pseudoalteromonas.     

Are the fish of the upper and lower Mekong interconnected？

The Mekong supports one of the richest inland fisheries in the world, with many of the fish migrating long distance to spawn. Little is known about the fisheries and migration strategies of the Upper Mekong whilst it is supposed that many fish species move between the Lower and Upper Mekong. Most likely, natural fish migration in the river has been altered by dam construction across the mainstream of the Upper Mekong. In this paper, the interconnectivity of fish species between different sections of the Mekong and negative impacts of dams on migratory fish are studied. Of the 162 fish species in the Upper Mekong and the 869 species in the Lower Mekong, 61 species are common. Results show that there is no significant difference at order level between the UM and LM. Similarity coefficients are used to evaluate interconnectivity at species, genus and family levels among four different sections of the Upper Mekong with each other and with the Lower Mekong as a whole. The highest similarity is found between the middle and lower reach of the Upper Mekong at species and genus levels and the middle and upper reach at family level. Of the eight cascade dams, Mengsong Dam in planning is considered as the biggest threat to migratory fish from the Lower Mekong and should be particularly concerned. Supported by National Natural Science Foundation of China (No. 40601096)     

Phylogenetic analysis of cultivable bacteria isolated from Arctic sea-ice

Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.     

Monophyly or polyphyly? Possible conflict between morphological and molecular interpretations of the wellknown genus Zoothamnium(Ciliophora,Peritrichia)

In this paper,we explore possible conflict between morphological and molecular interpretations of phylogenetic relationships within the well-known peritrichous genus Zoothamnium. On the basis of morphological evidence,for a long time this genus has been believed to be a well-defined monophyletic taxon. Nonetheless,Z oothamnium exhibits higher genetic diversity than the gross morphology of its species. Here,we used all available genetic information for the small subunit of ribosomal RNA(SSU r RNA) and internal transcribed spacer region(ITS1-5.8S-ITS2) for this genus to reconstruct phylogenies for four datasets(SSU rRNA,ITS1,ITS2,and ITS1-5.8S-ITS2) and a combined dataset(SSU rRNA+ITS1-5.8SITS2) using different phylogenetic methods and with consideration of the secondary structure of the genes. Confidence in phylogenetic tree selection was assessed with the approximately unbiased test. The molecular results showed both that Zoothamnium is more likely to be polyphyletic,and morphologically similar genera Zoothamnopsis and Myoschiston were always nested among Zoothamnium species. Accordingly,as with some other groups of ciliates,to understand more fully the correct phylogeny of Zoothamnium there remains a need for additional data from both morphological and molecular studies,covering additional Zoothamnium spp. and members of closely related genera(e.g. Zoothamnopsis,Myoschiston,and Epistylis).     

广西隆林祥播早二叠世茅口期的几种Pseudodoliolina

广西隆林祥播地区二叠纪地层是一套连续的海相碳酸盐岩,出露良好,内含丰富的(竹蜓)类化石。本文记述了Pseudodoliolina属的12种,其中对2个新种Pseudodoliolina contracta sp.nov.,P.subelliptica sp.nov.作详细描述。新种均采于茅口阶Cancellina带。新种的发现为本文论述Pseudodoliolina(竹蜓)类动物群的演化特征提供了实际材料。     

小东江茂名段浮游生物及污染状况分析

2007年7月对茂名市小东江的浮游生物及污染状况进行调查和分析,结果共检出浮游植物122种,其中蓝藻门15属34种,占(总种类数,下同)27.9%,硅藻门16属26种,占21.3%,绿藻门29属52种,占42.6%,裸藻门3属6种,占4.9%,金藻门1属1种,占0.8%,黄藻门3属3种,占2.5%;浮游动物78种,其中原生动物门26属36种,占46.2%,轮虫动物门9属16种,占20.5%,节肢动物门枝角类8属14种,占17.9%,桡足类10属11种,占14.1%,水生昆虫1属1种,占1.3%。各调查断面浮游植物的种类数平均为37种,细胞密度在11.3×104~19.5×104/L,Ⅴ断面最高,Ⅰ断面最低,平均为14.4×104/L;浮游动物种类数平均为27种,密度平均为2 895/L。相邻断面间Jaccard种类相似性指数范围为0.13~0.23,各断面环境异质性相差较大,该季节河水流动性小。叶绿素a含量为19.9~45.3μg/L,它与细胞密度呈显著的正相关,与无机氮、无机磷和COD均不存在明显的相关性。各断面的浮游植物多样性指数为3.1~4.5,均匀度为0.62~0.85;浮游动物的多样性指数为2.7~3.9,均匀度我0.59~0.80。对βm-αm指示种种类组成和群落结构分析,Ⅱ、Ⅲ、Ⅳ、Ⅴ断面水质属生态中污类型,而Ⅰ断面属生态寡污类型。以国家地表水质量标准评判,各断面COD含量为Ⅰ类水;无机氮含量除Ⅰ断面外,其他断面均为Ⅲ类水;无机磷含量均优于Ⅱ类水;石油类除Ⅰ、Ⅱ断面为Ⅳ类水外,其他断面均为Ⅴ类水。单因子污染指数分析表明,小东江流域水质为中污染至重污染之间。